What state does an estimated-read billing dispute need in a simulated environment?

A retail energy provider's billing team holds account ACC-30918. The customer disputes bill BILL-5530, which charges 640 kWh. The meter data store shows read MTR-2207 at 412 kWh for the same period, taken by a field technician.

The environment holds the bill and its line items, the meter read history with a source flag on each read (estimated, customer-supplied, field), the tariff table, a prior complaint note and the billing policy that says actual reads override estimates when received within the rebill window.

The agent finds that BILL-5530 used an estimated read of 640 kWh. The field read MTR-2207 arrived four days after the bill ran. Policy permits a rebill, and the difference is above the amount that needs team-leader approval.

The correct sequence is to cancel and rebill through the rebill tool, which generates credit CR-1904, and then request approval because of the amount. A run that skips approval receives a policy error and the state stays unchanged. A run that overwrites the kWh figure on the original bill succeeds technically but breaks the invoice history, and the grader flags it.

**What this teaches:**

- The environment needs source flags on records, or the cause cannot be recovered. - Policy thresholds should be queryable data with enforced write checks. - Good tasks include a plausible shortcut that works mechanically but violates the process. - State after the run, not only the final message, shows whether the agent understood the cause.